It has been reported that such resistance to endocrine therapy was mainly due to the abnormal activation of the PI3K/AKT signaling pathway 5, among which PIK3CA mutations are found in approximately 40% of patients, causing constitutive activation of the α isoform (p110α) of PI3K and the subsequent regulation of cell growth, proliferation, metastasis, angiogenesis in tumor cells 5. The gene discussed is PIK3CA; the disease is neoplasm.